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Journal of Zhejiang University (Agriculture and Life Sciences)  2024, Vol. 50 Issue (2): 209-220    DOI: 10.3785/j.issn.1008-9209.2023.12.183
    
Retrieval of soil moisture based on Gaofen-3 (GF-3) satellite synthetic aperture radar data over agricultural fields
Linlin ZHANG1,2,3(),Zhibin LEI4(),Liping WANG5,Qingyan MENG1,2,3(),Jiangyuan ZENG1
1.State Key Laboratory of Remote Sensing Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100101, China
2.University of Chinese Academy of Sciences, Beijing 100049, China
3.Key Laboratory of Earth Observation of Hainan Province, Hainan Aerospace Information Research Institute, Sanya 572029, Hainan, China
4.School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China
5.Center for Urban Governance Studies of Zhejiang Province, Hangzhou International Urbanology Research Center, Hangzhou 310000, Zhejiang, China
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Abstract  

Soil moisture is the basic condition for crop growth. A new retrieval algorithm for soil moisture was proposed based on C-band synthetic aperture radar (SAR) data from Gaofen-3 (GF-3) satellite, and soil moisture of agricultural fields with a regional scale spatial resolution of 8 m was obtained. First, the algorithm selected the optical vegetation water index based on PROSAIL model, measured vegetation canopy water content and Landsat-8 optical data. The parameters of water cloud model were calculated, and soil direct backscattering coefficients were obtained. Second, the radar backscattering influence mechanism was simulated using an advanced integral equation model (AIEM), and the combined roughness of soil surface was calculated based on the characteristics of radar data at high and low incidence angles. Finally, soil moisture was retrieved using co-polarization radar data from GF-3 satellite over agricultural fields, and this was verified with measured data. The results showed that there was a high consistency between the measured soil moisture and estimated soil moisture, and vertical-vertical (VV) polarization exhibited higher retrieval accuracy, with a determination coefficient of 0.595 6 and a root mean square error of 0.041 5 m3/m3. The results can provide algorithmic references for the GF-3 satellite to obtain high-resolution soil moisture information.



Key wordssoil moisture      Gaofen-3 (GF-3) satellite      radar remote sensing      soil surface roughness     
Received: 18 December 2023      Published: 25 April 2024
CLC:  P237  
Corresponding Authors: Qingyan MENG     E-mail: zhangll@aircas.ac.cn;1529418402@qq.com;mengqy@radi.ac.cn
Cite this article:

Linlin ZHANG, Zhibin LEI, Liping WANG, Qingyan MENG, Jiangyuan ZENG. Retrieval of soil moisture based on Gaofen-3 (GF-3) satellite synthetic aperture radar data over agricultural fields. Journal of Zhejiang University (Agriculture and Life Sciences), 2024, 50(2): 209-220.

URL:

https://www.zjujournals.com/agr/10.3785/j.issn.1008-9209.2023.12.183     OR     https://www.zjujournals.com/agr/Y2024/V50/I2/209


基于高分三号卫星合成孔径雷达数据的农田土壤水分反演

土壤水分是农作物生长的基本条件,本研究基于高分三号卫星C波段合成孔径雷达数据,提出新的土壤水分反演算法,并获取区域尺度8 m空间分辨率的农田区土壤水分。首先,通过PROSAIL模型、实测植被冠层含水量、Landsat-8光学数据优选光学植被水分指数,计算水云模型参数并获得土壤直接后向散射系数;其次,利用高级积分方程模型模拟雷达后向散射影响机制,采用雷达影像高低入射角特性计算地表组合粗糙度;最后,利用高分三号卫星同极化雷达数据反演农田区土壤水分,并基于实测数据开展精度验证。结果表明:土壤水分反演值与野外实测值具有良好一致性,垂直极化下反演精度更高,其决定系数为0.595 6,均方根误差为0.041 5 m3/m3。本研究成果可为我国自主研发的高分三号卫星获取高分辨率土壤水分信息提供算法参考。


关键词: 土壤水分,  高分三号卫星,  雷达遥感,  地表粗糙度 
Fig. 1 Backscattering coefficient of GF-3 satellite radar in study areaThe black dots represent sampling areas in the field experiment, and the legend represents the backscattering coefficient, dB.

植被水分指数

Vegetation water index

公式

Formula

文献

Reference

简单比值指数

Simple ratio index (SR)

SR=RNirRRed[22]

水胁迫指数

Moisture stress index (MSI)

MSI=RSwir1RNir[23]

归一化差异水指数1640

Normalized difference water index 1640 (NDWI1640)

NDWI1640=RNir-RSwir1RNir+RSwir1[24]
归一化差异水指数2201 NDWI2201NDWI2201=RNir-RSwir2RNir+RSwir2[24]

归一化植被指数

Normalized difference vegetation index (NDVI)

NDVI=RNir-RRedRNir+RRed[25]

归一化多波段干旱指数

Normalized multi-band drought index (NMDI)

NMDI=RNir-(RSwir1-RSwir2)RNir+(RSwir1+RSwir2)[26]

四波段干旱指数

Four band combined drought index (FCDI)

FCDI=RSwir1/RSwir2(RNir-RGreen)/(RNir+RGreen)[27]

增强型植被指数

Enhanced vegetation index (EVI)

EVI=2.5RNir-RRedRNir+6RSwir1-7.5RBlue+1[28]
Table 1 Computational formulas of eight vegetation water indexes
参数 Parameter范围/值 Range/value间隔 Interval
等效水厚度 Equivalent water thickness/(g/cm2)0.05~0.600.05
叶绿素含量 Chlorophyll content/(μg/cm2)20~6010
叶面积指数 Leaf area index1~61
干物质含量 Dry matter content/(g/cm2)0.001~0.0110.001
叶片结构 Leaf structure1.5
土壤系数 Soil coefficient1
太阳天顶角 Solar zenith angle/(°)65
观测天顶角 Viewing zenith angle/(°)29
平均叶倾角Mean leaf angle/(°)50
Table 2 Different parameters of PROSAIL model
Fig. 2 Correlation between vegetation water index and simulated vegetation canopy water content (VCWC)

植被水分指数

Vegetation water index

拟合公式

Fitting formula

决定系数

Determination coefficient (R2)

均方根误差

Root mean square error (RMSE)

MSIy=9.237 0e-3.696 3x0.625 80.387 6
NDWI1640y=0.388 1e3.955 0x0.634 20.386 1
NDWI2201y=0.216 9e3.675 1x0.601 70.396 9
NMDIy=0.078 9e6.434 2x0.614 30.392 7
Table 3 Correlation between vegetation water index and measured vegetation canopy water content in the field
Fig. 3 Soil direct backscattering coefficient imageA. Retrieved value from GF-3 satellite radar; B. Scatter plots of retrieved value from GF-3 satellite radar and simulated value from AIEM.
Fig. 4 Response of incidence angle to soil direct backscattering coefficient in different soil moisture conditions
Fig. 6 Response of combined roughness to soil direct back-scattering coefficient
 
Fig. 7 Three-dimensional relationship among soil direct backscattering coefficient, soil moisture and combined roughness
Fig. 8 Response of combined roughness to differences of soil direct backscattering coefficients at high and low incidence angles
Fig. 9 Soil moisture map retrieved by the GF-3 satellite radarPink patches represent villages.
Fig. 10 Scatter plots of retrieved and measured values of soil moisture
[1]   BOJINSKI S, VERSTRAETE M, PETERSON T C, et al. The concept of essential climate variables in support of climate research, applications, and policy[J]. Bulletin of the American Meteorological Society, 2014, 95(9): 1431-1443. DOI: 10.1175/bams-d-13-00047.1
doi: 10.1175/bams-d-13-00047.1
[2]   CARLSON T. An overview of the “triangle method” for estimating surface evapotranspiration and soil moisture from satellite imagery[J]. Sensors, 2007, 7(8): 1612-1629. DOI: 10.3390/s7081612
doi: 10.3390/s7081612
[3]   DIRMEYER P A. Using a global soil wetness dataset to improve seasonal climate simulation[J]. Journal of Climate, 2000, 13(16): 2900-2922.
[4]   JACKSON T J, BINDLISH R, COSH M H, et al. Validation of soil moisture and ocean salinity (SMOS) soil moisture over watershed networks in the U.S.[J]. IEEE Transactions on Geoscience and Remote Sensing, 2012, 50(5): 1530-1543. DOI: 10.1109/TGRS.2011.2168533
doi: 10.1109/TGRS.2011.2168533
[5]   ENGMAN E T. Progress in microwave remote sensing of soil moisture[J]. Canadian Journal of Remote Sensing, 1990, 16(3): 6-14.
[6]   ZHANG L L, MENG Q Y, HU D, et al. Comparison of different soil dielectric models for microwave soil moisture retrievals[J]. International Journal of Remote Sensing, 2020, 41(8): 3054-3069. DOI: 10.1080/01431161.2019.1698077
doi: 10.1080/01431161.2019.1698077
[7]   ZHANG L L, MENG Q Y, ZENG J Y, et al. Evaluation of Gaofen-3 C-band SAR for soil moisture retrieval using different polarimetric decomposition models[J]. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2021, 14: 5707-5719. DOI: 10.1109/JSTARS.2021.3083287
doi: 10.1109/JSTARS.2021.3083287
[8]   HUANG X D, WANG J F, SHANG J L. An adaptive two-component model-based decomposition on soil moisture estimation for C-band RADARSAT-2 imagery over wheat fields at early growing stages[J]. IEEE Geoscience and Remote Sensing Letters, 2016, 13(3): 414-418. DOI: 10.1109/LGRS.2016.2517082
doi: 10.1109/LGRS.2016.2517082
[9]   蒋金豹,胡丹娟,刘益青,等.基于MIMICS模型的麦田地表土壤含水量反演研究[J].麦类作物学报,2015,35(5):707-713. DOI:10.7606/j.issn.1009-1041.2015.05.20
JIANG J B, HU D J, LIU Y Q, et al. Research of soil moisture retrieval model of wheat covered surface based on MIMICS model[J]. Journal of Triticeae Crops, 2015, 35(5): 707-713. (in Chinese with English abstract)
doi: 10.7606/j.issn.1009-1041.2015.05.20
[10]   雷志斌,孟庆岩,田淑芳,等.基于GF-3和Landsat8遥感数据的土壤水分反演研究[J].地球信息科学学报,2019,21(12):1965-1976. DOI:10.12082/dqxxkx.2019.190115
LEI Z B, MENG Q Y, TIAN S F, et al. Soil moisture retrieval study based on GF-3 and Landsat8 remote sensing data[J]. Journal of Geo-information Science, 2019, 21(12): 1965-1976. (in Chinese with English abstract)
doi: 10.12082/dqxxkx.2019.190115
[11]   BAI X J, HE B B, LI X, et al. First assessment of Sentinel-1A data for surface soil moisture estimations using a coupled water cloud model and advanced integral equation model over the Tibetan Plateau[J]. Remote Sensing, 2017, 9(7): 714. DOI: 10.3390/rs9070714
doi: 10.3390/rs9070714
[12]   ATTEMA E P W, ULABY F T. Vegetation modeled as a water cloud[J]. Radio Science, 1978, 13(2): 357-364.
[13]   ULABY F T, SARABANDI K, MCDONALD K, et al. Michigan microwave canopy scattering model[J]. International Journal of Remote Sensing, 1990, 11(7): 1223-1253.
[14]   BRACAGLIA M, FERRAZZOLI P, GUERRIERO L. A fully polarimetric multiple scattering model for crops[J]. Remote Sensing of Environment, 1995, 54(3): 170-179.
[15]   方西瑶,蒋玲梅,崔慧珍.基于Sentinel-1雷达数据的青藏高原地区土壤水分反演研究[J].遥感技术与应用,2022,37(6):1447-1459. DOI:10.11873/j.issn.1004-0323.2022.6.1447
FANG X Y, JIANG L M, CUI H Z. Soil moisture retrieval in the Tibetan Plateau based on Sentinel-1 radar data[J]. Remote Sensing Technology and Application, 2022, 37(6): 1447-1459. (in Chinese with English abstract)
doi: 10.11873/j.issn.1004-0323.2022.6.1447
[16]   MENG Q Y, ZHANG L L, XIE Q X, et al. Combined use of GF-3 and Landsat-8 satellite data for soil moisture retrieval over agricultural areas using artificial neural network[J]. Advances in Meteorology, 2018, 2018: 9315132. DOI: 10.1155/2018/9315132
doi: 10.1155/2018/9315132
[17]   ZHANG L L, MENG Q Y, YAO S, et al. Soil moisture retrieval from the Chinese GF-3 satellite and optical data over agricultural fields[J]. Sensors, 2018, 18(8): 2675. DOI: 10.3390/s18082675
doi: 10.3390/s18082675
[18]   李震,陈权,任鑫.Envisat-1双极化雷达数据建模及应用[J].遥感学报,2006,10(5):777-782. DOI:10.11834/jrs.200605115
LI Z, CHEN Q, REN X. Modeling Envisat-1 dual-polarized data and its applications[J]. Journal of Remote Sensing, 2006, 10(5): 777-782. (in Chinese with English abstract)
doi: 10.11834/jrs.200605115
[19]   郑磊.基于微波遥感的裸露地表土壤水分反演研究[D].呼和浩特:内蒙古农业大学,2014.
ZHENG L. Research on bare surface soil moisture inversion based on the microwave remote sensing[D]. Hohhot: Inner Mongolia Agricultural University, 2014. (in Chinese with English abstract)
[20]   BOISVERT J B, GWYN Q H J, CHANZY A, et al. Effect of surface soil moisture gradients on modelling radar backscattering from bare fields[J]. International Journal of Remote Sensing, 1997, 18(1): 153-170.
[21]   张庆君.高分三号卫星总体设计与关键技术[J].测绘学报,2017,46(3):269-277. DO1: 10.11947/j.AGCS.2017.20170049
ZHANG Q J. System design and key technologies of the GF-3 satellite[J]. Acta Geodaetica et Cartographica Sinica, 2017, 46(3): 269-277. (in Chinese with English abstract)
doi: 10.11947/j.AGCS.2017.20170049
[22]   JORDAN C F. Derivation of leaf-area index from quality of light on the forest floor[J]. Ecology, 1969, 50(4): 663-666.
[23]   HUNT E R, Jr, ROCK B N. Detection of changes in leaf water content using near- and middle-infrared reflectances[J]. Remote Sensing of Environment, 1989, 30(1): 43-54.
[24]   CHEN D Y, HUANG J F, JACKSON T J. Vegetation water content estimation for corn and soybeans using spectral indices derived from MODIS near- and short-wave infrared bands[J]. Remote Sensing of Environment, 2005, 98(2/3): 225-236. DOI: 10.1016/j.rse.2005.07.008
doi: 10.1016/j.rse.2005.07.008
[25]   SERRANO L, USTIN S L, ROBERTS D A, et al. Deriving water content of chaparral vegetation from AVIRIS data[J]. Remote Sensing of Environment, 2000, 74(3): 570-581.
[26]   WANG L L, QU J J. NMDI: a normalized multi-band drought index for monitoring soil and vegetation moisture with satellite remote sensing[J]. Geophysical Research Letters, 2007, 34(20): L20405. DOI: 10.1029/2007GL031021
doi: 10.1029/2007GL031021
[27]   ZHANG J H, GUO W J. Quantitative retrieval of crop water content under different soil moistures levels[C]//SPIE Pro-ceedings, Volume 6411, Agriculture and Hydrology Applica-tions of Remote Sensing. Goa: SPIE, 2006: 85-93. DOI: 10.1117/12.697957
doi: 10.1117/12.697957
[28]   HUETE A, DIDAN K, MIURA T, et al. Overview of the radiometric and biophysical performance of the MODIS vegetation indices[J]. Remote Sensing of Environment, 2002, 83(1/2): 195-213. DOI: 10.1016/s0034-4257(02)00096-2
doi: 10.1016/s0034-4257(02)00096-2
[29]   CHENG Y B, ZARCO-TEJADA P J, RIAÑO D, et al. Estimating vegetation water content with hyperspectral data for different canopy scenarios: relationships between AVIRIS and MODIS indexes[J]. Remote Sensing of Environment, 2006, 105(4): 354-366. DOI: 10.1016/j.rse.2006.07.005
doi: 10.1016/j.rse.2006.07.005
[30]   马建新.农作物覆盖区土壤含水量多源遥感反演方法[D].焦作:河南理工大学,2016.
MA J X. Multi-source remote sensing inversion method of soil water content over agriculture fields[D]. Jiaozuo: Henan Polytechnic University, 2016. (in Chinese with English abstract)
[31]   CHEN K S, WU T D, TSANG L, et al. Emission of rough surfaces calculated by the integral equation method with comparison to three-dimensional moment method simulations[J]. IEEE Transactions on Geoscience and Remote Sensing, 2003, 41: 90-101. DOI: 10.1109/TGRS.2002.807587
doi: 10.1109/TGRS.2002.807587
[32]   ZENG J Y, CHEN K S, BI H Y, et al. A comprehensive analysis of rough soil surface scattering and emission predicted by AIEM with comparison to numerical simulations and experi-mental measurements[J]. IEEE Transactions on Geoscience and Remote Sensing, 2017, 55(3): 1696-1708. DOI: 10.1109/TGRS.2016.2629759
doi: 10.1109/TGRS.2016.2629759
[33]   ZRIBI M, DECHAMBRE M. A new empirical model to retrieve soil moisture and roughness from C-band radar data[J]. Remote Sensing of Environment, 2003, 84(1): 42-52. DOI: 10.1016/S0034-4257(02)00069-X
doi: 10.1016/S0034-4257(02)00069-X
[34]   KIM S B, TSANG L, JOHNSON J T, et al. Soil moisture retrieval using time-series radar observations over bare surfaces[J]. IEEE Transactions on Geoscience and Remote Sensing, 2012, 50(5): 1853-1863. DOI: 10.1109/TGRS.2011.2169454
doi: 10.1109/TGRS.2011.2169454
[35]   JACKSON T J, CHEN D Y, COSH M, et al. Vegetation water content mapping using Landsat data derived normalized difference water index for corn and soybeans[J]. Remote Sensing of Environment, 2004, 92(4): 475-482. DOI: 10.1016/j.rse.2003.10.021
doi: 10.1016/j.rse.2003.10.021
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